// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2014 Benoit Steiner <benoit.steiner.goog@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include "main.h"

#include <Eigen/CXX11/Tensor>

using Eigen::Tensor;

template<int DataLayout>
static void
test_simple_striding()
{
	Tensor<float, 4, DataLayout> tensor(2, 3, 5, 7);
	tensor.setRandom();
	array<ptrdiff_t, 4> strides;
	strides[0] = 1;
	strides[1] = 1;
	strides[2] = 1;
	strides[3] = 1;

	Tensor<float, 4, DataLayout> no_stride;
	no_stride = tensor.stride(strides);

	VERIFY_IS_EQUAL(no_stride.dimension(0), 2);
	VERIFY_IS_EQUAL(no_stride.dimension(1), 3);
	VERIFY_IS_EQUAL(no_stride.dimension(2), 5);
	VERIFY_IS_EQUAL(no_stride.dimension(3), 7);

	for (int i = 0; i < 2; ++i) {
		for (int j = 0; j < 3; ++j) {
			for (int k = 0; k < 5; ++k) {
				for (int l = 0; l < 7; ++l) {
					VERIFY_IS_EQUAL(tensor(i, j, k, l), no_stride(i, j, k, l));
				}
			}
		}
	}

	strides[0] = 2;
	strides[1] = 4;
	strides[2] = 2;
	strides[3] = 3;
	Tensor<float, 4, DataLayout> stride;
	stride = tensor.stride(strides);

	VERIFY_IS_EQUAL(stride.dimension(0), 1);
	VERIFY_IS_EQUAL(stride.dimension(1), 1);
	VERIFY_IS_EQUAL(stride.dimension(2), 3);
	VERIFY_IS_EQUAL(stride.dimension(3), 3);

	for (int i = 0; i < 1; ++i) {
		for (int j = 0; j < 1; ++j) {
			for (int k = 0; k < 3; ++k) {
				for (int l = 0; l < 3; ++l) {
					VERIFY_IS_EQUAL(tensor(2 * i, 4 * j, 2 * k, 3 * l), stride(i, j, k, l));
				}
			}
		}
	}
}

template<int DataLayout>
static void
test_striding_as_lvalue()
{
	Tensor<float, 4, DataLayout> tensor(2, 3, 5, 7);
	tensor.setRandom();
	array<ptrdiff_t, 4> strides;
	strides[0] = 2;
	strides[1] = 4;
	strides[2] = 2;
	strides[3] = 3;

	Tensor<float, 4, DataLayout> result(3, 12, 10, 21);
	result.stride(strides) = tensor;

	for (int i = 0; i < 2; ++i) {
		for (int j = 0; j < 3; ++j) {
			for (int k = 0; k < 5; ++k) {
				for (int l = 0; l < 7; ++l) {
					VERIFY_IS_EQUAL(tensor(i, j, k, l), result(2 * i, 4 * j, 2 * k, 3 * l));
				}
			}
		}
	}

	array<ptrdiff_t, 4> no_strides;
	no_strides[0] = 1;
	no_strides[1] = 1;
	no_strides[2] = 1;
	no_strides[3] = 1;
	Tensor<float, 4, DataLayout> result2(3, 12, 10, 21);
	result2.stride(strides) = tensor.stride(no_strides);

	for (int i = 0; i < 2; ++i) {
		for (int j = 0; j < 3; ++j) {
			for (int k = 0; k < 5; ++k) {
				for (int l = 0; l < 7; ++l) {
					VERIFY_IS_EQUAL(tensor(i, j, k, l), result2(2 * i, 4 * j, 2 * k, 3 * l));
				}
			}
		}
	}
}

EIGEN_DECLARE_TEST(cxx11_tensor_striding)
{
	CALL_SUBTEST(test_simple_striding<ColMajor>());
	CALL_SUBTEST(test_simple_striding<RowMajor>());
	CALL_SUBTEST(test_striding_as_lvalue<ColMajor>());
	CALL_SUBTEST(test_striding_as_lvalue<RowMajor>());
}
